KCET2011PhysicsMechanical Properties of Solids
The following four wires of length L and radius r are made of the same material. Which of these will have the largest extension, when the same tension is applied?
Options
- AL=100 ~cm , r=0.2 ~mm
- BL=200 ~cm , r=0.4 ~mm
- CL=300 ~cm , r=0.6 ~mm
- DL=400 ~cm , r=0.8 ~mm
Correct answer
A. L=100 ~cm , r=0.2 ~mm
Step-by-step solution
Extension of wire e= F L A Y e= F L r² Y F and Y are same for all wires aligned &e L r² &e_ a = 1000 0.2 0.2 =25000 &e_ b = 2000 0.4 0.4 =12500 &e_ c = 3000 0.6 0.6 =8333.4 &e_ d = 4000 0.8 0.8 =6250 aligned We can see that, first wire have the largest extension.